Least-Squares/ Galerkin Split Finite Element Method

ISBN-13: 9783659508516 / Angielski / Miękka / 2015 / 172 str.

Dennis Brian H.;Kumar Rajeev

Opis

The least-squares finite element method (LSFEM) has many attractive characteristics such as the lack of an inf-sup condition and the resulting symmetric positive system of algebraic equations unlike Galerkin finite element method (GFEM). However, the higher continuity requirements for second-order terms in the governing equations force the introduction of additional unknowns through the use of an equivalent first-order system of equations or the use of C¹ continuous basis functions, limiting the application of LSFEM to large-scale practical problems. A novel finite element method is proposed that employs a least-squares method for first-order derivatives and a Galerkin method for second order derivatives, thereby avoiding the need for additional unknowns required by a pure LSFEM approach. When the unsteady form of the governing equations is used, a streamline upwinding term is introduced naturally by the least-squares method. The method is stable for convection-dominated flows and allows for equal-order basis functions for both pressure and velocity. Various incompressible and compressible flow benchmark problems have been solved using low-order C⁰ continuous elements.

O autorze

Brian H Dennis, PhD is an Associate Professor in the Mechanical and Aerospace Engineering department at University of Texas at Arlington, TX. He teaches CFD, Finite Element Method, and Fluid Mechanics. His research interests span across design optimization, inverse problems, and computational fluid dynamics. He is a member of AIAA and ASME. Rajeev Kumar, PhD is currently an Adjunct Faculty in the Mechanical and Aerospace Engineering department at University of Texas at Arlington, TX. He has worked in University of Arizona, Tucson as Assistant Research Professor. His research interests span across FEM, experimental and computational fluid dynamics. He is a member of AIAA and ASME.